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W. E. McWHlRK, R. D. LEWIS & H. J. DESSON.

CLAM SHELL BUCKET.

APPLICATION flLED JAN. 8,1916.

1,193,706: Patented Aug. 8,1916.

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A TTORNEY W. E. McWHIRK, R. D. LEWIS & H. J. DESSON. CLAM SHELL BUCKET.

91 APPLICATION 'J 191s.

Patented Aug. 8, 1916.

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WARREN ELLSWORTH MGWHIRK, ROBERT DAVID LEWIS, AND HERBERT J'. DESSON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO THE McWI-IIRK ENGINEERING COMPANY, LTD., OF NIA'GARA FALLS, NEW YORK, A CORPORATION OF NEW YORK.

CLAIM-SHELL BUCKET.

Specification of-Letters latent.

Patented Aug. 8, 1916.

Application filed January 8, 1916. Serial No. 70,955.

I To all whom it may concern Be it known that we, WARREN ELLswoR'rH MGWHIRK, ROBERT DAVID LEWIS, and HER- BERT J. DESSON, citizens of the United States, residing at Pittsburgh, in the county of Al'- legheny and State of Pennsylvania, have invented certain new and useful Improvements in Clam-Shell Buckets, of which the following is a specification.

This invention relates to clam-shell buckets, and comprises the improvements herein shown and described and more particularly pointed out in the claims' Experience has demonstrated that the moving parts in a bucket using a freelyrunning closing line and embodying scoops, hinges, closing lever, etc., are brought to rest with much'impact when a positive stop is used. This impact, sooner or later, breaks or disarranges the positive stops and connecting parts and produces increased wear on the moving parts, in time rendering the bucket unfit for use due to the distortion of the parts.

The present bucket embodies a closing lever and an auxiliary lever connected with the closing cable and arranged'in .a particular way to strengthen the bucket in its digging and closing movements and to absorb the impact induced in rapidly opening the bucket. A supporting head or hanger and large diameter sheaves are also used in a articular way to decrease the wear on and lncrease the life of the closing cable and to compactly house the head sheaves and aline and easily fit the cables. An efiicient and easy digging bucket is also obtained by forming the main curve of the bottom of each scoop to approximate an are having its center at the hinge pin. Two of the closing-line sheaves are also mounted on the main head pin and the load imposed upon the head pin by diverging links or. bars connected with the outer corners of the hinged digging scoops, the object being to make the scoops do an equal amount of work.

In the accompanying drawings, Figure 1 is a side elevation of the bucket closed. Fig. 2 is a sectional view centrally through the bucket, showing the bucket wide open. Fig. 3 is an end view of the bucket closed and showing the head or housing partly in section.

The bucket comprises'a pair of clam-shell scoops 2, arranged with their respective digging lips 3 in opposed relations and connected together at each side in the plane of the r meeting edges by hinge arms 4 and 5 which are made relatively long to locate the hinge pin 6 thereof as near as practicable to the head of sheave hanger 7 and centrally 1n respect thereto. Relatively long hinge arms open the scoops 2 wide and gather a large amount of material together and also dig better. Moreover a long radius of movement is obtained for each scoop which permits the bottom 8 thereof to be formed on a curve or to. approximate an arc having its center at the hinge pin, thereby facilitating entrance of the scoops into the material and the gathering together of a large load with ammunum of resistance. The bucket also opens easily and clears itself very quickly of material due to the wide spread obtained through its relatively long hinge arms and such opening is also promoted by the weight of the sheave or drum 11 at the outer end I of the closing lever and the weight of the hubs and'other parts mounted on the hinge pm 6. The length of closing cable required to' be overhauled in opening the bucket is reduced to a minimum in order to open the bucket rapldly, and the end of this closing cable 12 is secured to one arm of a bellcrank or auxiliary lever 9 mounted to oscillate on the hinge-pin 6 between the sides of the double or bifurcated main lever 10 which is pinned or splined to the same hinge pin 6 between the two setsof hinge arms. Main lever 10 extends in a straight line from the upper outer edge of one of the scoops to the middle part of the hinge pin and the lower end thereof is rigidly secured by rivets or other means to the scoop, while the upper end of this lever extends be end the hinge pin and carries the narrowaced drum 11 of relatively large diameter within the space or channel within the lever. The bell-crank or auxiliary lever 9 is also located in this space oixchannel and adapted to rock Within limits therein, and the closing cable 12 extends from said lever 9 to the large 14 at the side of sheave 13. The closing line 12 in passing from sheave 13 to drum 11 and from drum ll to sheave 15 has an almost perfect lead, the correction in lead between ,5 sheave-13 and sheave 15 being taken care of by the narrow-faced drum 11 in passing around which the rope 12 describes a spiral movement. Both the head sheaves 13 and 15 on shaft 14 are inclosed within the head or hood 7, which also comprises a clevis or shackle having parallel links 17 pivotally attached thereto at its top by bolts to which the hold line 18 is fastened in any suitable way. The shaft 14 extends through the side and middle walls or plates 16 of the head or hood and two pairs of diverging bars 19 are suspended therefrom and have pivoted connection with the projecting corner pieces 25 of the scoops 2. The entire weight of the 20 bucket and load is carried in this way by the single central shackle bolt 14, and by mounting the sheaves 13 and 15 at the side of each other. upon this shackle-bolt within the hood or head, no brackets, shafts or other supplementary supports are required for the sheaves and the working and wearing parts are reduced to the least number, and the centralized relations of the suspensory parts also act to close the scoops 2 simultaneously in digging. Moreover, the hood-shaped clevis or head plates 16 serve as a rope guard, and the sheaves are compactly housed, while at the same time relatively large-sized sheaves are used which eliminates short turns and reduces the wear on the cables.

Head 7 is prevented from rotating around the head pin 14 and fouling the closing line by braces 21 riveted 0r bolted to one set of corner bars 19, and a short link 23 is also attached to the head plates ldfrom which a stop chain 22 is' suspended, theother or '-lower end of said chain being attached to the arm 24 of the bell-crank or auxiliary lever 9-. The bell-crank or auxiliary lever 9 and chain 22 act as a shock absorber, by causing the taut end of the closing cable fastened to arm 20 of lever 9 to be paid out faster as the hinge pin 6 is lowered and approaches the limit of its opening stroke, this operation requiring a short interval, of time for the cable to accelerate its speed. The energy of the moving parts is used in obtaining this acceleration and instead of being dissipated almost instantly, and with great impact asis the case with a positive stop, is distributed over some distance of travel of the moving parts and they are thus brought to rest gradually. Thus at the beginning of the opening movement of they bucket the closing cable end and the arm 20 are alined with the hinge pin 6, the other arm 24 of the bell-crank being in rest engagement with the main lever 10, which is provided with open keepers or stop lugs 26 adapted to seat the opposite ends of the chain connecting-pin 27 at the outer end of arm 24. Consequently, as the bucket opens the bell crank turns with the scoop carrying main lever 10 until the slack in chain 22 is taken up. The moment the chain becomes taut the downward movement of arm 24 is arrested and the bell crank rotated on hinge pin 6 during the final lowering and opening of the bucket. The result is that arm 20 of the bell crank describes a short arc at an a ccelerated speed as compared with the main lever 10 and the opening movement of the scoops is gradually checked in a corresponding degree through the closing cable. Moreover, the closing power of the bucket is increased at the beginning of the stroke, by the use of the auxiliary lever, as the stop chain acts as an additional element in the closing tackle, giving a four part closing line. Thus during the initial closing movements of the bucket the arm 20 of the bell crank or auxiliarylever 9 is raised and rotated by the closing cable, the rotary movement being centered at the chain connecting-pin 27 and the hinge pin 6 rising in less degree and slower than the arm 20 .and the closing cable end. However, when the pin 27 on arm 24 is carried into the rests 26 on main lever 10 the bell-crank or auxiliary lever 9 is prevented from rotating independently of the main lever and the arm 20 is brought to'rest in the most advantageous position for obtaining the maximum closing efiect from the pull in the closingcable.

The extended closing lever 10 being rigidly connected with the scoop and also mounted on the hinge pin to which it is keyed or otherwise secured, makes a very strong brace for the scoop at its top and center, and the power is also applied the'reby to better advantage in closing the scoop. The multiple reeving of the closing line to I the head sheaves and lever drum also enables the maximum closing power to be applied through this rigid lever and as this lever is anchored to the scoop in bracing relation to the hinge arms, all torsional stresses are practically eliminated at thehinge pin, and thedanger of shearing and loosening the arms from the scoop is also overcome. The hub or barrel of the main lever 10 is extended to fill the space between the hinge arms at the hinge pin 6 and may be made to suit any Width of bucket without change in the hinge arms, and the two sets of hinge arms are preferably independent castings attached to the scoops at their lower ends by rivets or otherwise and converging and offset at their upper ends to establish the desired relations at the opposite ends of the hinge pins.-

The closing cable 12 "passes out of the head 16 at one side. of the vertical center line, the distance depending on the diameter of the sheave 15 used, and this eccentricity of the closing cable may be varied by using sheaves of different diameters and compeneating for the non-concurrence of the center of gravity of the bucket on the vertical center line of same. The eccentricity is on the side of the bucket in which the extended lever arm 10 is anchored, and a bucket constructed as herein described is well balanced and evenly hung and one which will not tip or spill its contents.

What we claim is:

1. In a device of the kind described, bucket sections. in hinged connection, supporting means for said sections, a closing lever for said sections, sheaves mounted upon said lever and supporting means, a pivoted lever carried by said bucket, a closing cable connected with said pivoted lever and rove upon said sheaves, and means to impart an independent movement to said pivoted lever during opening movements of the bucket sections.

2. In a clam-shell bucket, a set of hinged scoops having a closing lever, an oscillatory lever and a closing cable connected therewith, and means to produce an independent movement of said oscillatory lever during opening movements of said scoops.

3. In a clamshell bucket, a setof hinged scoop members, a closing lever for one of scoop members, means to hold said members in a suspended position, a closing cable and a closing lever for said members, apivoted lever mounted to oscillate within predetermined stop limits and connected with said closing cable, and an operating connection extending from said holding means to said pivoted lever.

5. In a clam-shell bucket, a set of scoops having a hinge pin, holding means and a closing cable and lever for said scoops, an auxiliary lever rotatably mounted upon said hingepin and connected with said cable, stops for said auxiliary lever, and a flexible connection between said auxiliary lever and said holding means to actuate said lever during opening and closing movements of said scoop members for the purposes described.

6. A clam-shell bucket comprising hinged scoops having a closing lever, supportlng means and a closing cable for said scoops, a lever membermounted in pivoted relation to said closing lever and connected with said closing cable, stops to limit the movement .of said lever member, and a take-up operating connection for said lever member extending from said supporting means to said lever member.

In testimony whereof we aflix our signatures in presence of two Witnesses.

WARREN ELLSWORTH MOWHIRK. ROBERT DAVID LEWIS. HERBERT J. DESSON. Witnesses:

ALICE A. TRILL, ANNA KELLY. 

